Model Output Discussion - Autumn arrives

[minus10]

7 minutes ago, Battleground Snow said:

Hard to tell by the colour scale, but 598-600 dam is exceptionally rare even in France, let alone the UK 

Yes, looking at thickness on netweather chart seems very high coming up from the south..

 

[Summer Sun]

37c on Saturday in the south

[clark3r]

If gfs still showing this in a couple of days I think the meto will need to issue weather warnings for a danger to life this is exceptional and in uk will be very uncomfortable 

[kold weather]

2 minutes ago, Summer Sun said:

37c on Saturday in the south

Thats the 00z run, the 06z GFS is lower around 34-35c on Saturday, BUT is stronger with the heat afterwards.

[ancientsolar]

Just now, clark3r said:

If gfs still showing this in a couple of days I think the meto will need to issue weather warnings for a danger to life this is exceptional and in uk will be very uncomfortable 

Yes, agreed, i'm actually wondering if there are any warnings already out for France. 

 

[East_England_Stormchaser91]

8 minutes ago, MattStoke said:

That would be the heatwave to end all heatwaves.

Surely that would warrant a state of emergency? Those temperatures both day and night are truly unprecedented. 

[Cambrian]

20 minutes ago, kold weather said:

Yeah, we saw what happened in W.Canada when a heat dome sets in, all sorts of records can get blastered as the heat just builds and sits.

The GFS basically evolves into that, the ECM 00z is REAL close to doing the same. Luckily we are at the NW edge of any such heat dome, so any sort of attack from the west should drive away the really extreme heat however it suggests well above average temps will be here to stay for some time.

Could become an exceptional heatwave for the south in particular even without the really severe heat that the recent OP runs have been giving.

This kinda feels like the hot version of the beast from the east.

The grill from Seville.

[Scorcher]

2 minutes ago, East_England_Stormchaser91 said:

Surely that would warrant a state of emergency? Those temperatures both day and night are truly unprecedented. 

Maybe someone can enlighten me here, but how much extra danger is there with temps of 42C compared to temps in the 36-39C range which although extremely rare have happened in the UK before?

A lot of people talking about how dangerous this could be- I don't think it's quite at that level in terms of danger to life. Fires could be another issue however,

[sheikhy]

Plume is back with a vengeance on the 06z!!!wow!!!

[qwertyK]

4 minutes ago, East_England_Stormchaser91 said:

Surely that would warrant a state of emergency? Those temperatures both day and night are truly unprecedented. 

Probably because it's still unlikely. I can't remember if it was 2019 or 2020, or one of those two summers where there was also speculation this sort of scenario would occur. 

 

It didn't. 

[tight isobar]

2 minutes ago, qwertyK said:

Probably because it's still unlikely. I can't remember if it was 2019 or 2020, or one of those two summers where there was also speculation this sort of scenario would occur. 

 

It didn't. 

But- we are in formed/ evolution.. time ahead.. of what is supported, and expected @ thermo increases!.. this being a “ get used to”- prognosis!!!!- the long construction plots scream these outcomes!

Edited July 10, 2022 by tight isobar

[qwertyK]

Just now, tight isobar said:

But- we are in formed/ evolution.. time ahead.. of what is supported, and expected @ thermo increases!.. this being a “ get used to”- prognosis!!!!

49C on the northern coast of france and 43C in the southeast of the UK sounds insanely high. Things like cloud cover may also prevent 40C being reached. 

The weather shows Paris will be be 39C on the 16th/17C and that's always a few degrees hotter than London. I think max of 36C in the UK. 

[kold weather]

7 minutes ago, Scorcher said:

Maybe someone can enlighten me here, but how much extra danger is there with temps of 42C compared to temps in the 36-39C range which although extremely rare have happened in the UK before?

A lot of people talking about how dangerous this could be- I don't think it's quite at that level in terms of danger to life. Fires could be another issue however,

The August 2020 heatwave I believed caused about 2500 extra deaths in 2020. The set-up being progged on the 06z GFS is another level above that again. Its closer to what France had in 2003 and that led to 10,000 extra deaths in terms of how under prepared and anomalous that heat was for them.

It absolutely is a huge risk to life, especially with buildings that are not prepared for it at all and a population that has no idea how to handle it either. 

EDIT - for younger people it will be manageable bar the risk of heat stroke/drowning. Its the elderly and the very young that will struggle though.

Edited July 10, 2022 by kold weather

[Mike Poole]

3 minutes ago, qwertyK said:

Probably because it's still unlikely. I can't remember if it was 2019 or 2020, or one of those two summers where there was also speculation this sort of scenario would occur. 

 

It didn't. 

No.  There hasn’t been a previous summer, as long as I have been watching the models, where 40C+ temperatures showed up on any of the main models, let alone repeatedly on multiple runs of multiple models.  This scenario may still not happen, but it is categorically different from anything we have discussed in past years re UK summer high temperatures.  

[MattStoke]

3 minutes ago, qwertyK said:

49C on the northern coast of france and 43C in the southeast of the UK sounds insanely high. Things like cloud cover may also prevent 40C being reached. 

The weather shows Paris will be be 39C on the 16th/17C and that's always a few degrees hotter than London. I think max of 36C in the UK. 

Air looks dry with very low due points and the low not close enough to introduce any instability or moisture so I’d be surprised if there was any cloud cover.

It’s about a perfect a setup as is possible for record breaking heat, if the plume should make a direct or near direct hit.

Edited July 10, 2022 by MattStoke

[tight isobar]

3 minutes ago, qwertyK said:

49C on the northern coast of france and 43C in the southeast of the UK sounds insanely high. Things like cloud cover may also prevent 40C being reached. 

The weather shows Paris will be be 39C on the 16th/17C and that's always a few degrees hotter than London. I think max of 36C in the UK. 

Indeed- however!.. you couldn’t have wished/ dreaded for perfect exactions for heat limpit stomp! As the ground -/ immediate overheads are set@ ideal for geographical extremism. Due to lag and already backing up of low/ mid layered!!!!! Which by way of simple physics will just have jet engine effect....

Edited July 10, 2022 by tight isobar

[ChannelThunder]

10 minutes ago, Cambrian said:

The grill from Seville.

If we see certain newspapers using that phrase as a headline, we'll know they've been here!

[mb018538]

More about education really. 40c doesn’t need to be dangerous if you are sensible….millions of people manage it for months on end every year. UK suffers more as our houses are built to retain heat.

[kold weather]

Just now, Mike Poole said:

No.  There hasn’t been a previous summer, as long as I have been watching the models, where 40C+ temperatures showed up on any of the main models, let alone repeatedly on multiple runs of multiple models.  This scenario may still not happen, but it is categorically different from anything we have discussed in past years re UK summer high temperatures.  

Not just that but we had a HUGE warning shot across the bows in June 2019 when we were a ENE at the surface away from reaching 40-42c back then as well. I've been banging on ever since then saying we should be able to reach 41-42c in the right setup. The thickness and 850hpa certainly supported it, we just had a big undercut from the North Sea. Not looking that likely that saves us this time around.

I'll admit I'm still sceptical we go quite to the heights of the GFS, but even if we don't, the 4th year out of 5 with a 36c+ weather should be another huge warning shot for many.

[qwertyK]

2 minutes ago, MattStoke said:

Air looks dry with very low due points and the low not close enough to introduce any instability or moisture so I’d be surprised if there was any cloud cover.

It’s about a perfect a setup as is possible for record breaking heat, if the plume should make a direct or near direct hit.

If this really is the case, why isn't the Met Office or government warning about it?

In all the heatwaves we've had, we've never managed to break out to 39C, never mind 43C, if the record is broken it will be be a degree max, by 4.3C would be bonkers. I withold my judgement for now

[MattStoke]

Just now, qwertyK said:

If this really is the case, why isn't the Met Office or government warning about it?

In all the heatwaves we've had, we've never managed to break out to 39C, never mind 43C, if the record is broken it will be be a degree max, by 4.3C would be bonkers. I withold my judgement for now

Because it’s 7 days away.

[qwertyK]

1 minute ago, kold weather said:

Not just that but we had a HUGE warning shot across the bows in June 2019 when we were a ENE at the surface away from reaching 40-42c back then as well. I've been banging on ever since then saying we should be able to reach 41-42c in the right setup. The thickness and 850hpa certainly supported it, we just had a big undercut from the North Sea. Not looking that likely that saves us this time around.

I'll admit I'm still sceptical we go quite to the heights of the GFS, but even if we don't, the 4th year out of 5 with a 36c+ weather should be another huge warning shot for many.

We didn't have 36C last year? In fact, we barely got to 33C? 

 

[Singularity]

From reading around, the airmass we may import from the south undergoes huge adiabatic descent over Spain, causing to become extremely hot and dry, typical of what’s seen over the Sahara under the subtropical high pressure belt.

This implies legit potential to deliver temps into the 40s with relative humidity below 20%. Damaging to many indigenous plants if it happens.

However, I’ve also seen mention of something called the ‘Bowen Ratio’ which reportedly GFS makes too high for extremely dry airmasses, leading to some excess surface heating, so it may have a positive bias of 1-2*C for the peak of the heat. Alarmingly, when applied to the 06z, this still allows for 40*C in some spots on at least one day.

[qwertyK]

Just now, MattStoke said:

Because it’s 7 days away.

Suggesting there is still plenty of time for things to change. My money's on it being in the low to mid thirties, 33-36C, maybe 37. 

[Southern Storm]

16 minutes ago, Scorcher said:

Maybe someone can enlighten me here, but how much extra danger is there with temps of 42C compared to temps in the 36-39C range which although extremely rare have happened in the UK before?

A lot of people talking about how dangerous this could be- I don't think it's quite at that level in terms of danger to life. Fires could be another issue however,

This was posted yesterday

11 hours ago, gaia rules said:

The humidity therefore night temperatures will be important in predicting impact on health. I set up the Heat Health warnings when I worked as health lead at the Met Office after the 2003 European Heat wave and it was the night-time temperatures that mattered more. In France  those living above the high floors of tower blocks who  died as temperatures cooled from the ground up. The higher humidity meant that there were high min temps. So far the predicted humidity next weekend is very low  so although the temperatures are frighteningly high if the humidity stays low and there are no more than 2 nights in a row with minima of 22 then it may not be so catastrophic on health.

So not an exact comparison, but the original poster gives some idea of what could come to pass in an extreme event 

Edited July 10, 2022 by Southern Storm